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The sources of morphological variation in natural populations of Fucus distichus L. ssp. edentatus (De la Pyiaie) Powell and F. distichus L. ssp, evanescens (C. Agardh) Powell from New England were evaluated. Individuals from different populations were morphologically distinct as judged by population means and analysis of variance. A correlation between the plant's form and its habitat was established by field observation. The broadest material grows in calm estuarine habitats, while the narrowest plants occur in exposed, open coastal areas. Major differences in morphology also appear seasonally. In addition, microhabitat factors such as exposure to wave action and elevation explain some morphological variation. Cultured germlings from distinct populations of “evanescens” and “edentatus” type plants were outplanted to an experimental garden in order to ascertain whether the variation was heritable or environmentally induced. The latter experiments indicate that major differences in morphology are genetically determined. 相似文献
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The paper describes a hydrodynamic method by which the adhesive strength of the mucilage produced from the apical proes of Closterium acerosum has been measured. An equation used to determine the drag force on the cells is presented, as are some measured adhesive strengths of the Closterium mucus to glass slides. 相似文献
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Peter Bond Murray Brown Roy Moate Martha Gledhill Stephen Hill Malcolm Nimmo 《欧洲藻类学杂志》2013,48(5):513-521
Exposure of Fucus spiralis germlings to precise copper concentrations (0 to 844?nM?Cu2+) in chemically defined medium demonstrated a relationship between ultrastructural changes and growth retardation with increasing copper concentration. Electron-translucent vesicles, present in ova, which normally disappear after fertilization, accumulated in germlings exposed to Cu2+ above 10.6?nM, suggesting that copper may inhibit a metabolic pathway involved in cell wall formation which is initiated by fertilization. No membrane damage was observed during the exposure period. During a post-exposure period in copper-free medium, recovery occurred (rhizoid extension, apical hair formation) in germlings previously exposed to concentrations below 106?nM?Cu2+ and electron-translucent vesicles became granular and disappeared. It is proposed that the electron-translucent vesicles contain a cell wall precursor and that copper inhibits its incorporation into the cell wall, preventing growth and development of the zygote. 相似文献
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DARRYL W M COOK PETER G LONG SIVA GANESH HUGH F NEILSON 《The Annals of applied biology》1997,131(2):213-226
An apparatus and protocol for the efficient and consistent isolation of bacteria and yeasts with the ability to attach to germlings of Botrytis cinerea is described. The study focused on minimising microbial contamination by bacteria or yeasts which do not attach to the pathogen B. cinerea but which interact with materials used in the equipment and would otherwise be isolated along with target microbes. After development, the assay reduced the contamination rate to 1–2 cells per 100 added and this was found to be a satisfactory level for the selection of microbial attachers to fungal hyphae. One or more phenotypes of microbes that adhered to B. cinerea germlings were found in 97% of the 70 samples collected from phylloplane washings and processed using this assay. 相似文献
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Experiments were carried out with three-year-old embryogenic suspension culture of Gentiana pannonica Scop. The initial explant for the suspension determinated both the embryogenic character and embryo production. Cultures
were initiated by culture of hypocotyl, cotyledon and root explants on MS (Murashige and Skoog 1962) medium supplemented with
1.0 mg·l−1 Kinetin and 0.5 mg·l−1 2,4-D, later transferred and maintained in liquid MS medium with 1.0 mg·l−1 Dicamba, 0.1 mg·l−1 NAA, 2.0 mg·l−1 BAP and 80.0 mg·l−1 AS. Regeneration medium included 0.0–1.0 mg·l−1 GA3+0.0−2.0 mg·l−1 Kin.+0.0−160 mg·l−1 AS.
In these culture conditions, the effect of the explant was found to be the most important factor. The curve of growth, growth
coefficient and % of participation of various size aggregates differed in the studied suspensions. Flow cytometry revealed
various DNA content in nuclei from praembryogenic mass depending on the explant origin. To complete embryogenesis the medium
was changed from liquid to solidified in the presence of the same plant growth regulators combination required. The most embryogenic
culture appeared hypocotyl-derived and it yielded the highest number of somatic embryos. The suspension culture originating
from root proliferated the highest number of embryogenic cell clusters but did not produce embryos for fraction 120–450 μm.
One hundred mg of suspension of the fraction that was larger than 450 μm yielded 309, 175, 123 embryos for the following suspensions:
root-, cotyledon-, hypocotyl-derived, respectively. Almost 50 % of non-deformed fully developed embryos from all studied suspensions
passed conversion into germling stage and finally plants were regenerated. 相似文献
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Ogarkova O. A. Tomilov A. A. Tomilova N. B. Tarasov V. A. 《Russian Journal of Developmental Biology》2004,35(3):174-181
A group of 13 recessive lethal mutants was selected on the basis of the collection of Arabidopsis thaliana transgenic plants with insertions of T-DNA vector plasmid pLD3 or pPCVRN4, which was produced by agrobacterial transformation of germinating seeds. The use of media containing exogenous hormones made it possible to compensate the lethal effect, identify phenotypes, and characterize six lines of recessive lethal germlings using genetic and molecular-genetic methods. 相似文献
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Laboratory and field studies on growth of Sarcothalia crispata, whichis one of the most important carrageenophytes of Chile, were made in toassess its viability and growth in a system of suspended culture. Invitro experiments on the survival of the germlings and on the effect oftemperature and irradiance on its growth allowed to determine the besttemperature and irradiance for seeding polypropylene culture ropes inindoors conditions. The growth of plants developed on ropes at threedepths in Coliumo Bay (central Chile) supports the idea that it is feasiblebiologically to manage the resource via aquaculture. Fouling and epiphyteswere the main problem at the experimental site. The results suggest thatmaintaining the cultures in deeper water during summer could minimize thisproblem. 相似文献
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